This K01 mentored award proposal aims to develop an independent investigator specializing in cancer comparative effectiveness research (CER) who combines patient-centered research, outcomes evaluation, and decision-analysis modeling in order to improve the quality of evidence-based practice in cancer care. I am an Assistant Professor of Oncology and a member of the Lombardi Comprehensive Cancer Center at Georgetown University. My pharmacy background and my research training in cancer epidemiology have motivated me to pursue a research career that contributes to high-quality cancer care in the United States. My career development plan consists of didactic education (formal coursework and training workshops) and a mentored research project with three research aims. This award is designed to fill gaps in my training and research experience, specifically in engaging stakeholders for research and developing Markov decision- analysis models to facilitate clinical decision making. Additionally, this award will provide training in methodology and analysis I have yet to receive in regards to assessing effectiveness, safety and patient- reported outcomes in an observational setting. My mentored research project is an exemplar CER project and aims to compare two hormonal therapy approaches: intermittent versus continuous administration of androgen deprivation therapy (ADT) in advanced prostate cancer. I have proposed this research project because ADT is used as primary treatment in prostate cancer control and its optimal administration remains unclear based on current evidence from clinical trials. I will leverage a longitudinal cohort created through collaboration with a large integrated health plan, which includes rich cancer registry information merged with comprehensive electronic clinical encounter data, pharmaceutical data, and laboratory values. I will compare all-cause and disease-specific survival (Aim1: effectiveness) and risk of serious side effects (Aim 2: safety) of intermittent versus continuous ADT. I then will integrate Aims 1 and 2 findings with published data on patients' preference into a decision-analysis model to project patients' quality-adjusted-life-expectancy on these two types of ADT (Aim 3). Findings from the proposed study will contribute knowledge not provided by existing clinical trials. I will conduct this mentored award in the established and supportive training environment of the Lombardi Comprehensive Cancer Center with an expert team of researchers in health services research, clinical medicine, health economics, and biostatistics. I also will seek guidance from an advisory board consisting of patients, caregivers, physicians, and a behavioral researcher about how best to communicate study findings and shape my future research to address the needs of cancer patients and survivors. After completion of this mentored award, I will have acquired expertise in evidence generation and integration of outcomes important to clinical decision-making. I will also be well prepared to apply the cancer CER expertise gained from this research experience to a broad array of emerging and novel treatment interventions in cancer care.